Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
A typical image forming apparatus using an electrophotographic method includes a fixing device having a pressure roller that is brought into pressure contact with a fixing roller. The fixing device applies pressure and heat to sheets passing between the two rollers (through a fixing nip) to fix toner images on the sheets (fixing process). The sheets enter the fixing nip while the surface on which the toner image is transferred is opposed to the fixing roller side.
Sheets having passed through the fixing nip can become wound around the fixing roller due to the viscousness of the melted toner. On this account, the fixing device includes a separation claw in constant contact with the surface of the fixing roller. This separation claw prevents a sheet from becoming wound around the fixing roller after the fixing process. A problem, however, is that the separation claw being constantly in contact with (slidably contacting) the fixing roller makes the fixing roller liable to being abraded.
There is proposed a technique to solve the above-described problem. For example, there is proposed a fixing device including a mechanism (solenoid) that causes a separation claw to contact and be separated from a fixing roller. This mechanism is controlled such that the separation claw contacts the fixing roller only when the fixing process is performed.